Sidelink control information indication

ABSTRACT

Apparatuses, methods, and systems are disclosed for sidelink control information indication. One apparatus includes a receiver that receives a second control information message from a remote unit over sidelink communication. Here, the second control information message is in response to the remote unit receiving one or more data processes scheduled by a first control information message from a relay unit. The apparatus also includes a processor that determines a transmission-reception pattern for the sidelink communication and generates an indicator of the determined transmission-reception pattern. The apparatus further includes a transmitter that transmits the indicator of the determined transmission-reception pattern to the remote unit in a third control information message.

FIELD

The subject matter disclosed herein relates generally to wirelesscommunications and more particularly relates to providing sidelinkcontrol information indication.

BACKGROUND

The following abbreviations and acronyms are herewith defined, at leastsome of which are referred to within the following description.

Third Generation Partnership Project (“3GPP”), Positive-Acknowledgment(“ACK”), Channel State Information (“CSI”), Control Channel (“CCH”),Device-to-Device (“D2D”), Downlink Control Information (“DCI”), Downlink(“DL”), Downlink Pilot Time Slot (“DwPTS”), Evolved Node B (“eNB”),European Telecommunications Standards Institute (“ETSI”),Frequency-Division Multiplexing (“FDM”), Frequency Division MultipleAccess (“FDMA”), Guard Period (“GP”), Hybrid Automatic Repeat Request(“HARQ”), Long Term Evolution (“LTE”), LTA Advanced (“LTE-A”), MediumAccess Control (“MAC”), Multiple Access (“MA”), Modulation Coding Scheme(“MCS”), Mobility Management Entity (“MME”), Machine Type Communication(“MTC”), Narrowband (“NB”), Negative-Acknowledgment (“NACK”) or (“NAK”),Next Generation Node B (“gNB”), Orthogonal Frequency DivisionMultiplexing (“OFDM”), Packet Data Convergence Protocol (“PDCP”), PacketData Network (“PDN”), PDN Gateway (“P-GW”), Physical Broadcast Channel(“PBCH”), Physical Downlink Control Channel (“PDCCH”), Physical DownlinkShared Channel (“PDSCH”), Physical Sidelink Control Channel (“PSCCH”),Physical Sidelink Shared Channel (“PSSCH”), Physical Hybrid ARQIndicator Channel (“PHICH”), Physical Random Access Channel (“PRACH”),Physical Resource Block (“PRB”), Physical Uplink Control Channel(“PUCCH”), Physical Uplink Shared Channel (“PUSCH”), Quality of Service(“QoS”), Radio Resource Control (“RRC”), Receive (“RX”), Serving Gateway(“S-GW”), Scheduling Assignment (“SA”), Scheduling Request (“SR”),Shared Channel (“SCH”), Sidelink Control Information (“SCI”), SystemInformation Block (“SIB”), Transport Block (“TB”), Transport Block Size(“TBS”), Transmission Control Protocol (“TCP”), Time-DivisionMultiplexing (“TDM”), Transmission and Reception Point (“TRP”),Transmission Time Interval (“TTI”), Transmit (“TX”), Uplink ControlInformation (“UCI”), User Datagram Protocol (“UDP”), UserEntity/Equipment (Mobile Terminal) (“UE”), Uplink (“UL”), UniversalMobile Telecommunications System (“UMTS”), Uplink Pilot Time Slot(“UpPTS”), Vehicle-to-Vehicle (“V2V”), and Worldwide Interoperabilityfor Microwave Access (“WiMAX”). As used herein, “HARQ-ACK” may representcollectively the Positive Acknowledge (“ACK”) and the NegativeAcknowledge (“NAK”). ACK means that a TB is correctly received while NAKmeans a TB is erroneously received.

In mobile communication networks, a remote UE may operate in an indirectcommunication mode where the remote UE accesses mobile networkcommunication services via a relay UE. Both D2D and V2V communicationsare broadcast-based communications. However, broadcast-basedcommunications do not meet requirements on QoS, reliability, complexityand power consumption.

BRIEF SUMMARY

Methods for sidelink control information indication are disclosed.Apparatuses and systems also perform the functions of the methods. Onemethod of a relay UE for sidelink control information indicationincludes receiving a second control information message from a remoteunit over sidelink communication. Here, the second control informationmessage is in response to the remote unit receiving one or more dataprocesses scheduled by a first control information message from a relayunit. The method includes determining a transmission-reception patternfor a remote unit using sidelink communication and generating anindicator of the determined transmission-reception pattern. The methodfurther includes transmitting the indicator to the remote unit in athird control information message.

One method of a remote UE for sidelink control information indicationincludes receiving an indicator of a transmission-reception pattern in afirst control information message and receiving an indicator ofscheduling assignment transmitted in the first control informationmessage and associated data transmitted in a data channel from a relayunit. The method also includes generating an indicator of hybridautomatic repeat request (“HARQ”) feedback information in response toreceiving one or more data processes and determining a transmissionsubframe of the apparatus based on the received indicator of atransmission-reception pattern. The method further includes transmittingthe indicator of HARQ feedback information to the relay unit in a secondcontrol information message on a remote unit transmission subframedetermined from the transmission-reception pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of the embodiments briefly described abovewill be rendered by reference to specific embodiments that areillustrated in the appended drawings. Understanding that these drawingsdepict only some embodiments and are not therefore to be considered tobe limiting of scope, the embodiments will be described and explainedwith additional specificity and detail through the use of theaccompanying drawings, in which:

FIG. 1 is a schematic block diagram illustrating one embodiment of awireless communication system for sidelink control informationindication;

FIG. 2 is a block diagram illustrating one embodiment of communicationbetween a remote UE and a relay UE for sidelink control informationindication;

FIG. 3 is a table illustrating one embodiment of predeterminedtransmission-reception patterns for sidelink control informationindication;

FIG. 4 is a block diagram illustrating another embodiment ofcommunication between a remote UE and a relay UE for sidelink controlinformation indication;

FIG. 5 is a block diagram illustrating another embodiment ofcommunication between a remote UE and a relay UE for sidelink controlinformation indication;

FIG. 6 is a schematic block diagram illustrating one embodiment of aremote UE apparatus for sidelink control information indication;

FIG. 7 is a schematic block diagram illustrating one embodiment of arelay UE apparatus for sidelink control information indication;

FIG. 8 is a schematic flow chart diagram illustrating one embodiment ofa method for sidelink control information indication; and

FIG. 9 is a schematic flow chart diagram illustrating another embodimentof a method for sidelink control information indication.

DETAILED DESCRIPTION

As will be appreciated by one skilled in the art, aspects of theembodiments may be embodied as a system, apparatus, method, or programproduct. Accordingly, embodiments may take the form of an entirelyhardware embodiment, an entirely software embodiment (includingfirmware, resident software, micro-code, etc.) or an embodimentcombining software and hardware aspects.

For example, the disclosed embodiments may be implemented as a hardwarecircuit comprising custom very-large-scale integration (“VLSI”) circuitsor gate arrays, off-the-shelf semiconductors such as logic chips,transistors, or other discrete components. The disclosed embodiments mayalso be implemented in programmable hardware devices such as fieldprogrammable gate arrays, programmable array logic, programmable logicdevices, or the like. As another example, the disclosed embodiments mayinclude one or more physical or logical blocks of executable code whichmay, for instance, be organized as an object, procedure, or function.

Furthermore, embodiments may take the form of a program product embodiedin one or more computer readable storage devices storing machinereadable code, computer readable code, and/or program code, referredhereafter as code. The storage devices may be tangible, non-transitory,and/or non-transmission. The storage devices may not embody signals. Ina certain embodiment, the storage devices only employ signals foraccessing code.

Any combination of one or more computer readable medium may be utilized.The computer readable medium may be a computer readable storage medium.The computer readable storage medium may be a storage device storing thecode. The storage device may be, for example, but not limited to, anelectronic, magnetic, optical, electromagnetic, infrared, holographic,micromechanical, or semiconductor system, apparatus, or device, or anysuitable combination of the foregoing.

More specific examples (a non-exhaustive list) of the storage devicewould include the following: an electrical connection having one or morewires, a portable computer diskette, a hard disk, a random-access memory(“RAM”), a read-only memory (“ROM”), an erasable programmable read-onlymemory (“EPROM” or Flash memory), a portable compact disc read-onlymemory (“CD-ROM”), an optical storage device, a magnetic storage device,or any suitable combination of the foregoing. In the context of thisdocument, a computer readable storage medium may be any tangible mediumthat can contain, or store a program for use by or in connection with aninstruction execution system, apparatus, or device.

Reference throughout this specification to “one embodiment,” “anembodiment,” or similar language means that a particular feature,structure, or characteristic described in connection with the embodimentis included in at least one embodiment. Thus, appearances of the phrases“in one embodiment,” “in an embodiment,” and similar language throughoutthis specification may, but do not necessarily, all refer to the sameembodiment, but mean “one or more but not all embodiments” unlessexpressly specified otherwise. The terms “including,” “comprising,”“having,” and variations thereof mean “including but not limited to,”unless expressly specified otherwise. An enumerated listing of itemsdoes not imply that any or all of the items are mutually exclusive,unless expressly specified otherwise. The terms “a,” “an,” and “the”also refer to “one or more” unless expressly specified otherwise.

Furthermore, the described features, structures, or characteristics ofthe embodiments may be combined in any suitable manner. In the followingdescription, numerous specific details are provided, such as examples ofprogramming, software modules, user selections, network transactions,database queries, database structures, hardware modules, hardwarecircuits, hardware chips, etc., to provide a thorough understanding ofembodiments. One skilled in the relevant art will recognize, however,that embodiments may be practiced without one or more of the specificdetails, or with other methods, components, materials, and so forth. Inother instances, well-known structures, materials, or operations are notshown or described in detail to avoid obscuring aspects of anembodiment.

Aspects of the embodiments are described below with reference toschematic flowchart diagrams and/or schematic block diagrams of methods,apparatuses, systems, and program products according to embodiments. Itwill be understood that each block of the schematic flowchart diagramsand/or schematic block diagrams, and combinations of blocks in theschematic flowchart diagrams and/or schematic block diagrams, can beimplemented by code. This code may be provided to a processor of ageneral-purpose computer, special purpose computer, or otherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer orother programmable data processing apparatus, create means forimplementing the functions/acts specified in the schematic flowchartdiagrams and/or schematic block diagrams.

The code may also be stored in a storage device that can direct acomputer, other programmable data processing apparatus, or other devicesto function in a particular manner, such that the instructions stored inthe storage device produce an article of manufacture includinginstructions which implement the function/act specified in the schematicflowchart diagrams and/or schematic block diagrams.

The code may also be loaded onto a computer, other programmable dataprocessing apparatus, or other devices to cause a series of operationalsteps to be performed on the computer, other programmable apparatus, orother devices to produce a computer implemented process such that thecode which execute on the computer or other programmable apparatusprovide processes for implementing the functions/acts specified in theschematic flowchart diagrams and/or schematic block diagram.

The schematic flowchart diagrams and/or schematic block diagrams in theFigures illustrate the architecture, functionality, and operation ofpossible implementations of apparatuses, systems, methods, and programproducts according to various embodiments. In this regard, each block inthe schematic flowchart diagrams and/or schematic block diagrams mayrepresent a module, segment, or portion of code, which includes one ormore executable instructions of the code for implementing the specifiedlogical function(s).

It should also be noted that, in some alternative implementations, thefunctions noted in the block may occur out of the order noted in theFigures. For example, two blocks shown in succession may, in fact, beexecuted substantially concurrently, or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved. Other steps and methods may be conceived that are equivalentin function, logic, or effect to one or more blocks, or portionsthereof, of the illustrated Figures.

The description of elements in each figure may refer to elements ofproceeding figures. Like numbers refer to like elements in all figures,including alternate embodiments of like elements.

In order to meet requirements on QoS, reliability, complexity and powerconsumption, unicast-based sidelink communications are provided.Disclosed herein are methods, apparatus, and systems that support arelay UE to perform the resource allocation for sidelink communication,indicate the data transmission and/or feedback information transmissionfrom the remote UE. As described herein, the relay UE determines atransmission-reception pattern and generates an indicator of the same.The transmission-reception pattern indicator allows a remote UE toidentify a relay UE reception frame, where the remote UE is permitted totransmit data and/or HARQ feedback information. Additionally, the relayUE and/or remote UE may send SCI that contains a scheduling assignmentfunction differentiation flag that to differentiate an associated datatransmission from a feedback ACK/NACK information transmission.

FIG. 1 depicts a wireless communication system 100 for sidelink controlinformation indication, according to embodiments of the disclosure. Inone embodiment, the wireless communication system 100 includes remoteunits 105, base units 110, and communication links 115. Even though aspecific number of remote units 105, base units 110, and communicationlinks 115 are depicted in FIG. 1, one of skill in the art will recognizethat any number of remote units 105, base units 110, and communicationlinks 115 may be included in the wireless communication system 100.

In one implementation, the wireless communication system 100 iscompliant with the LTE, LTE advanced and subsequent cellular networksystem specified in the 3GPP specifications. More generally, however,the wireless communication system 100 may implement some other open orproprietary communication network, for example, WiMAX, among othernetworks. The present disclosure is not intended to be limited to theimplementation of any particular wireless communication systemarchitecture or protocol.

In one embodiment, the remote units 105 may include computing devices,such as desktop computers, laptop computers, personal digital assistants(“PDAs”), tablet computers, smart phones, smart televisions (e.g.,televisions connected to the Internet), smart appliances (e.g.,appliances connected to the Internet), set-top boxes, game consoles,security systems (including security cameras), vehicle on-boardcomputers, network devices (e.g., routers, switches, modems), or thelike. In some embodiments, the remote units 105 include wearabledevices, such as smart watches, fitness bands, optical head-mounteddisplays, or the like. Moreover, the remote units 105 may be referred toas subscriber units, mobiles, mobile stations, users, terminals, mobileterminals, fixed terminals, subscriber stations, UE, user terminals, adevice, or by other terminology used in the art. The remote units 105may communicate directly with one or more of the base units 110 viauplink (“UL”) and downlink (“DL”) communication signals. Furthermore,the UL and DL communication signals may be carried over thecommunication links 115. In addition, the remote units 105 maycommunicate indirectly with a base unit 110 via a relay unit 120. Here,a relay unit 120 communicates with one or more remote units 105 usingsidelink communication signals carried over one or more relay links 125.A relay unit 120 is a remote unit 105 that also serves as a relay forone or more additional remote units 105.

The base units 110 may be distributed over a geographic region. Incertain embodiments, a base unit 110 may also be referred to as anaccess terminal, a base, a base station, a Node-B, an eNB, a gNB, a HomeNode-B, a relay node, a femtocell, an access point, a device, or by anyother terminology used in the art. The base units 110 are generally partof a radio access network (“RAN”) that may include one or morecontrollers communicably coupled to one or more corresponding base units110. These and other elements of radio access network are notillustrated but are well known generally by those having ordinary skillin the art. The base units 110 connect to the mobile core network 130via the RAN.

The base units 110 may serve a number of remote units 105 within aserving area, for example, a cell or a cell sector via a wirelesscommunication link. The base units 110 may communicate directly with oneor more of the remote units 105 via communication signals. The baseunits 110 communicate directly with the one or more relay units 120 viathe communication signals. Generally, the base units 110 transmitdownlink (“DL”) communication signals to serve the remote units 105and/or relay units 120 in the time, frequency, and/or spatial domain.Furthermore, the DL communication signals may be carried over thecommunication links 115. The communication links 115 may be any suitablecarrier in licensed or unlicensed radio spectrum. The communicationlinks 115 facilitate communication between one or more of the remoteunits 105 (and/or relay units 120) and one or more of the base units110.

The wireless communication system 100 includes one or more relay units120 capable of relaying traffic of the remote units 105 to the baseunits 110. As noted above, the relay units 120 are remote units 105capable of relaying the traffic between a base unit 110 and anotherremote unit 105. As such, a relay unit maintains its own networkconnections. In one embodiment, a relay unit 120 may communicate with aremote host 155 via a network connection with a base unit 110 and themobile core network 130. The remote units 105 and relay units 120communicate using relay links 125. In one embodiment, the relay links125 may be any suitable carrier in licensed or unlicensed radiospectrum. Examples of relay links 125 include, but are not limited toLTE-direct links, WiFi-direct links, and the like.

In one embodiment, the mobile core network 130 is an evolved packet core(“EPC”). In another embodiment, the mobile core network 130 may be a 5Gcore network. The mobile may be coupled to a data network 150, like theInternet and private data networks, among other data networks. In someembodiments, the remote units 105 and/or relay units 120 communicatewith a remote host 155 via a network connection with the mobile corenetwork 130. Each mobile core network 130 belongs to a single publicland mobile network (“PLMN”). The present disclosure is not intended tobe limited to the implementation of any particular wirelesscommunication system architecture or protocol.

The mobile core network 130 includes several network elements. Asdepicted, the mobile core network 130 includes at least one MME 135, atleast one S-GW 140, and at least one P-GW 145. Although a specificnumber of MMEs 135, S-GWs 140, and P-GWs 145 are depicted in FIG. 1, oneof skill in the art will recognize that any number of MMEs 135, S-GWs140, and P-GWs 145 may be included in the mobile core network 130.

The MME 135 is a control plane network element that handles signalingrelated to mobility and security for the remote unit 105. The MME 135 isa termination point for a NAS connection of the remote unit 105 to themobile core network 130. The S-GW 140 is a user plane element thatconnects the RAN to the mobile core network 130. The S-GW 140 serves theremote unit 105 by routing incoming/outgoing IP packets. The P-GW 145 isa user plane element that connects the mobile core network 130 to anexternal (IP) network, such as the data network 150.

As depicted, a relay unit 120 may provide a remote unit 105 with accessto a base unit 110. A relay unit 120 used sidelink communications tocommunicate with one or more remote units 105. To facilitate thesidelink communication, the relay unit 120 may indicate atransmission-reception pattern to the remote unit 105, e.g., usingsidelink control information (“SCI”) sent on a PSCCH, as discussed ingreater detail below. Additionally, the remote unit 105 and/or relayunit 120 may indicate whether a SCI message includes feedbackinformation and/or is associated with a data transmission on thesidelink data channel, as discussed in greater detail below.

FIG. 2 depicts communication 200 for sidelink control informationindication between a remote UE 205 and a relay UE 210, according toembodiments of the disclosure. The remote UE 205 may be one embodimentof a remote unit 105, while the relay UE 210 may be one embodiment of arelay unit 120. The remote UE 205 and relay UE 210 communicate usingsidelink communication over a D2D connection. Here, the sidelinkcommunication includes a plurality of subframes 225-250. As depicted, afirst portion of the subframes are Relay UE Transmission subframes and asecond portions of the subframes are Relay UE Reception subframes.During a Relay UE Transmission subframe, the relay UE 210 is scheduledto transmit data, signaling, feedback information, and the like to oneor more remote UEs 205. During a Relay UE Reception subframe, the relayUE 210 is scheduled to receive data, signaling, feedback information,and the like from the one or more remote UEs.

The number and location of the Relay UE Transmission subframes and RelayUE Reception subframes forms the transmission-reception pattern 215 forthe sidelink communication. In order for the remote UE 205 and the relayUE 210 to successfully communicate each must know thetransmission-reception pattern 215. In the depicted embodiment, therelay UE 210 generates the transmission-reception pattern 215 andtransmits an indicator of the transmission-reception pattern (item 220)to the remote UE 205.

In this case, when the relay UE 210 transmits a data transmission, therelay UE 210 needs to determine and generate an indicator 220 of thetransmission-reception pattern 215 so that the remote UE 205 canidentify at least one Relay UE Reception subframe, as shown in FIG. 2.The remote UE 205 provides feedback of the decoding status (e.g., HARQACK/NACK) of one or more data transmission(s) it receives from the relayUE 210.

First, the relay UE 210 determines the transmission-reception pattern215 for sidelink communication between one or more remote UE(s) 205.After determining the transmission-reception pattern 215, the relay UE210 generates an indicator 220 of the transmission-reception pattern. Insome embodiments, the indicator 220 of the transmission-receptionpattern is transmitted in a sidelink control information (“SCI”)message.

In some embodiments, the relay UE 210 determines thetransmission-reception pattern 215 by selecting from a set of predefinedpatterns. FIG. 3 shows a table of eight different predefined patterns.In certain embodiments, the transmission-reception pattern 215 isselected based on the ratio of payload size to be transmitted betweenrelay UE 210 and remote UE 205 on sidelink.

The payload size of the relay UE 210 is based on the payload size to betransmitted from the relay UE 210 to the remote UE 205. The payload sizeof the remote UE 205 is based on the payload size to be transmitted fromthe remote UE 205 to the relay UE 210. The information of payload (size)of the remote UE 205 may be obtained via a SR (scheduling request) or aBSR (Buffer Status Report) received by an eNB or relay UE 210.

The buffer status of the relay UE 210 is used for the relay UE 210 todetermine the number of relay UE transmission subframes (e.g., thenumber of reception subframes for the remote UE 205). The information ofbuffer status of the relay UE 210 is based on triggered traffic on therelay UE 210 side. The buffer status report (“BSR”) of the remote UE 205is based on the triggered traffic on the remote UE 205 side. The remoteUE 205 reports the BSR to the relay UE 210 in a BSR MAC control element(e.g., transmitted in UL data channel for legacy UE to eNBtransmission). After receiving the BSR of the remote UE 205, the relayUE 210 may determine the number of relay UE reception subframe (e.g.,the number of transmission subframes for the remote UE).

In certain embodiments, the transmission-reception pattern 215 isgenerated by the relay UE 210 and may or may not conform to one of thepredefined patterns. Here, the generated transmission-reception pattern215 may also be based on the ratio of payload size to be transmittedbetween relay UE 210 and remote UE 205 on sidelink.

As depicted in FIG. 2, the relay UE 210 transmits data to the remote UE205 in four subframes 225-240 and the remote UE 205 receives the dataduring these subframes. Here, the remote UE 205 is to respond to thefour subframes transmissions in one subframe. In the depictedembodiment, the payload size ratio is 4:1 and the transmission-receptionpattern 215 is four transmission subframes on relay UE 210 side to onereception subframe on relay UE 210 side. In certain embodiments, thetransmission-reception pattern 215 may be represented in bitmap manner,e.g., 5 bits (11110), in sidelink control information. Here, a value of“1” in the bitmap indicates that the subframe is a Relay UE Transmissionsubframe, while a value of “0” indicates that the subframe is a Relay UEReception subframe.

While the embodiments of FIG. 2 depict the relay UE 210 determining thetransmission-reception pattern 215, in other embodiments thetransmission-reception pattern 215 may be generated by the eNB, e.g.,based on the ratio of payload size to be transmitted between relay UE210 to and remote UE(s) 205 on sidelink. In such embodiments, thetransmission-reception pattern 215 is then transmitted from the eNB (notshown) to the relay UE 210. Alternatively, the eNB may transmit thetransmission-reception pattern 215 to both relay UE 210 and remote UE(s)205 by downlink control information.

In one embodiment, the indicator 220 of the transmission-receptionpattern may be an indication of one or more next reception subframes onthe relay UE 210 side (e.g., indicate Relay UE Reception subframes).Here, the relay UE 210 may determine the next one reception subframe(e.g., to receive the transmission from the remote UE 205) and then therelay UE 210 generates an indicator of next one reception subframepattern. For example, a 4-bit value of “0111” may be included in SCI toindicate that the n+7 subframe is used for relay UE 210 reception (i.e.,receiving and detecting remote UE 205 transmission). Generally, theindicator of a next reception subframe must point to a subframe farenough ahead in time for the remote UE 205 to process the SCI and switchto transmission mode.

In the depicted embodiment, the relay UE 210 may send an indicator witha value of “0100” (binary “4”) during subframe #0 (subframe 225) toindicate that the next relay UE reception subframe is n+4 subframes away(e.g., the next UE reception subframe is subframe #4). Similarly, insubframe #1 (subframe 230) the indicator may have a value of “0011”(binary “3”) and in subframe #2 (subframe 235) the indicator may have avalue of “0010” (binary “2”), each indicator pointing to the subframe #4(subframe 245) as the next relay UE reception subframe.

However, in subframe #3 (subframe 240), there is insufficient processingtime to point to the subframe #4 (subframe 245). Thus, in subframe #3(subframe 240) the indicator may have a value of “0110” (binary “6”) toindicate that the next relay UE reception subframe is n+4 subframes away(e.g., the next UE reception subframe is subframe #9). In anotherembodiment, the indicator 220 of the transmission-reception pattern maybe an indication of one or more next transmission subframes on the relayUE 210 side (e.g., indicate Relay UE Transmission subframes).

FIG. 3 depicts a table 300 with predetermined transmission-receptionpatterns 325. Here, ‘T’ represents the transmission subframe(s) on relayUE 210 side and ‘R’ represents the reception subframe(s) on relay UE 210side). The table 300 includes a transmission-to-reception configuration305. Each transmission-to-reception configuration 305 corresponds to oneof the predetermined transmission-reception patterns 325. The relay UE210 may send, as the indicator 220, a binary value corresponding to thetransmission-to-reception configuration 305.

The table 300 also includes transmission-to-reception switch-pointperiodicity information 310 when indicates a periodicity with which apredetermined transmission-reception pattern 325 switches from relay UEtransmission to relay UE reception, and back again. For example, thetransmission-reception pattern 215 shown in FIG. 2 may correspond to thetransmission-to-reception configuration #3 and have atransmission-to-reception switch-point periodicity of 5 ms (eachsubframe being 1 ms in duration).

Returning to FIG. 2, the relay UE 210 transmits the indicator 220 of thetransmission-reception pattern to the remote UE 205. In someembodiments, the indicator 220 is sent in a SCI message. The indicator220 of pattern may be represented by a plurality of bits (e.g., 3, 4 or5 bits) in the SCI. As a first example, a bitmap indicator 220 of thetransmission-reception pattern may use 5 bits to represent thetransmission-reception pattern 215 in the following 5 subframes. Asmentioned above, a ‘1’ may be used to represent a transmission subframeand a ‘0’ may be used to represent a reception subframe. Using thisconvention, the transmission-reception pattern 215 may be indicatedusing the bitmap “11110”.

In another embodiment, the indicator 220 of the transmission-receptionpattern may use one or more bits to indicate the next one receptionsubframe (or alternative the next one transmission subframe). Asmentioned above, a four-bit indicator 220 of “0111” may be used toindicate that the n+7 subframe is used for relay UE 210 reception (e.g.,the remote UE 205 may transmit data or feedback information in thissubframe). Alternatively, a three-bit indicator 220 of “110” may be usedto indicate that the n+6 subframe is to be used for relay UEtransmission (e.g., the remote UE 205 is to receive data or feedbackinformation in this subframe).

In certain embodiments, the indicator 220 may include one or more bitsrepresenting one of a set of pre-defined transmission-reception patterns215. For example, a three-bit indicator 220 may be used to represent oneof a set of pre-defined pattern configurations in FIG. 3. Specifically,an indicator 220 of ‘100’ indicates the transmission-to-receptionconfiguration #4 where the first nine subframes (subframe 0-8) in oneframe (10 ms) are used for relay UE 210 transmission and the lastsubframe (subframe 9) is used for relay UE 210 reception.

In certain embodiments, the indicator 220 may include additionalinformation. In a first example, an indicator of scheduling assignment(“SA”) may indicate a time/frequency resource of feedback information.In a second example, an indicator of SA may indicate a time offsetand/or frequency offset based on the transmission resource of the relayUE 210. In a third example, an indicator of SA may indicate the timeoffset only. Here, the frequency resource is same as relay UE 210transmission (SA and/or data) resource. In a fourth example, the timeoffset is preconfigured or fixed (e.g., n+4) and the frequency resourceis same as the relay UE 210 transmission (SA and/or data) resource. In afifth example, the indicator 220 may indicate a preconfigured or fixedtime/frequency offset for resource hopping.

As discussed above, the relay UE 210 may send the indicator 220 of thetransmission-reception pattern in a SCI message. Besides the indicator220 of the transmission-reception pattern, the SCI transmitted fromrelay UE 210 to remote UE 205 may include a flag for schedulingassignment function differentiation. The SA function differentiationflag may be a 1- or 2-bit flag used to differentiate a SA is used toindicate its associated data transmission from a feedback ACK/NACKinformation transmission. The SA function differentiation flag aids theremote UE 205 in interpreting the SCI message.

In some embodiments, the SA function differentiation flag is a 1-bitflag that indicates whether this SCI includes only an indication offeedback information transmission or whether it includes both anindication of data transmission and an indication of feedbackinformation transmission. For example, a value of ‘0’ may indicate thatthe SCI message contains an indication of feedback information, while avalue of ‘1’ may indicate that this SCI message include both anindication of data transmission and the indication of feedbackinformation. Alternatively, a value of ‘1’ may indicate that this SCIincludes only an indication of feedback information, while a value of‘0’ may indicate that this SCI includes both an indication of datatransmission and an indication of feedback information. The SA functiondifferentiation flag is further explained with reference to FIG. 4.

FIG. 4 depicts communication 400 for sidelink control informationindication between the remote UE 205 and the relay UE 210, according toembodiments of the disclosure. Note that the remote UE 205 and the relayUE 210 communicate over sidelink using a transmission-reception pattern415 where the subframe 425 (subframe #0) is a Relay UE ReceptionSubframe and the subframes 430-445 are Relay UE Transmission Subframes.

As depicted, the relay UE 210 receives a data transmission from theremote UE 205 in subframe #0 (subframe 425) and attempts to transmitfeedback information (e.g., HARQ feedback) corresponding to subframe #0(subframe 425) in subframe #2 (relay UE 210 transmission subframe).However, the remote UE 205 does not know a priori (e.g., it cannotforesee) whether the relay UE 210 has data to be transmitted in subframe#2 to remote UE 205 or whether the relay UE 210 only has feedbackinformation to transmit. Here, the SA function differentiation flag isincluded in SCI transmitted by the relay UE 210 so that the remote UE205 is able to determine whether the SCI transmitted in subframe #2includes an indication of feedback information transmission only orwhether this SCI includes both an indication of data transmission and anindication of feedback information.

In certain embodiments, the SA function differentiation flag may be a1-bit flag to indicate whether this sidelink control informationincludes an indication of data transmission or whether this sidelinkcontrol information includes ACK/NACK feedback information. In suchembodiments, the SCI will not have both an indication of datatransmission and ACK/NACK feedback information. For example, a value of‘0’ may indicate that this SCI includes an indication of datatransmission only, while a value of ‘1’ may indicate that this SCIincludes an indication of feedback information only. Alternatively, avalue of ‘1’ may indicate that this SCI includes an indication of datatransmission only, while a value of ‘0’ may indicate that this SCIincludes an indication of feedback information only.

In some embodiments, the SA function differentiation flag may be a 2-bitflag that indicates whether this SCI includes an indication of datatransmission only (e.g., indicated using a value of ‘00’), whether thisSCI includes an indication of feedback information transmission only(e.g., indicates using a value of ‘01’), or whether this SCI includesboth an indication of data transmission and feedback informationtransmission (e.g., indicated using a value ‘10’). As only threescenarios are mapped, one value of the 2-bit flag (e.g., the value ‘11’)is reserved (e.g., not to be used).

In some embodiments, the content of the SCI varies based on the SAfunction differentiation flag. For example, if the flag for SA functiondifferentiation is set to indicate data transmission only, then the SCIshould include the following bits to indicate data transmission relevantinformation: a HARQ process number (e.g., 3 bits); a resource allocationindication of SA associated data (e.g., 12 bits); a time gap between theSA and its associated data (e.g., 4 bits), a frequency resource locationof SA associated data (e.g., 8 bits), or some combination thereof; amodulation and coding scheme (e.g., 5 bits); a modulation and codingscheme of SA associated data (e.g., 5 bits); and a new data indicator(e.g., 1 bit). Note that the time gap information is used to support FDMbetween PSCCH/PSSCH from the system perspective, but TDM from the UEperspective.

As another example, if the flag for SA function differentiation is setto indicate ACK/NACK feedback information only, then the SCI may bemodified to indicate ACK/NACK feedback relevant information. Here, theabove bits of HARQ process number (3 bits) and modulation and codingscheme (5 bits), may be used to indicate ACK/NACK feedback in bitmanner. Moreover, these 8 bits may represent the decoding status of 8HARQ process numbers in bitmap manner, e.g., using ‘1’ to represent ACKstatus and ‘0’ to represent NACK status. Here, one or more of these bitsmay be used to indicate DTX status where the remote UE 205 did not usethis HARQ process number for transmission. Accordingly, if the remote UE205 transmitted the data transmission with HARQ process number, it willcheck the corresponding HARQ process number bit of 8 bits. Here, thevalue of ‘01111011’ can represent HARQ process #7 and #2 are decodedunsuccessfully or didn't used for transmission, while the otherprocesses (e.g., #6, #5, #4, #3, #1, and #0) are decoded successfully.

As yet another example, if the flag for SA function differentiation isset to indicate both ACK/NACK feedback information and data transmissiontogether, then the SCI may indicate both data transmission relevantinformation and ACK/NACK feedback relevant information. In certainembodiments, this may require new bit fields to be defined for HARQACK/NACK feedback in SCI. Here, a new 8-bit field may be defined toconvey HARQ feedback information in the manner described above.

FIG. 5 depicts communication 500 for sidelink control informationindication between the remote UE 205 and the relay UE 210, according toembodiments of the disclosure. Here, the remote UE 205 sends SCI andassociated data to the relay UE 210. To do so, the remote UE 205 firstdetermines the transmission subframe for sidelink communication based ontransmission and reception configuration (e.g., based on thetransmission-reception pattern 515). In one embodiment, the transmissionand reception configuration may be received from relay UE 210 insidelink control information. For example, the relay UE 210 may send SCIcontaining the indicator 220 of the transmission-reception patterndiscussed above. In another embodiment, the transmission and receptionconfiguration may be received from an eNB (not shown) in downlinkcontrol information. Here, the remote UE 205 determines to transmit SCIcontaining an indicator of feedback information and an indicator ofassociated data in subframe 530 (“Subframe #1).

Next, the remote UE 205 generates an indicator of HARQ feedbackinformation based on the decoding status of each relay UE 210transmission subframe. As discussed above, the indicator of HARQfeedback information may be a bitmap (e.g., 8-bit bitmap), e.g., using‘1’ to represent ACK status and ‘0’ to represent NACK status. Becausethe relay UE 210 cannot know ahead of time whether the remote UE 205will transmit feedback information, an indicator of data transmission,or both feedback information and an indicator of data transmission inthe SCI of Subframe #1 (subframe 530), the generates a flag for SAfunction differentiation. Here, the SA function differentiation flaggenerated by the remote UE 205 is substantially as that generated by therelay UE 210 described above.

Because there is an associated data transmission (e.g., the remote UE205 transmits data on same subframe), the remote UE 205 generates theadditional data transmission relevant information in SCI as discussedabove. Then in Subframe #1, the remote UE 205 transmits the indicator520 of (HARQ) feedback information and indication of associated datatransmission in SCI. Here, the remote UE 205 transmits the associateddata using the sidelink data channel.

In some embodiments, the remote UE 205 and/or the relay UE 210 may reusethe SCI format 1 when sending the above described indicators in SCI.Here, certain bit fields of the SCI format 1 are replaces with the abovedescribed indicators, requiring a receiving UE to reinterpret the SCIformat 1 in order to receive the indicators.

Generally, the SCI format 1 contains 3 bits of priority information, 4bits of resource reservation, a system-specific number of bits offrequency resource location of initial transmission and retransmission(e.g., using ┌log₂(N_(subchannel) ^(SL)+1)/2)┐ bits, whereN_(subchannel) ^(SL) refers to the number of subchannels allocated forsidelink communication), 4 bits of time gap information (time gapbetween initial transmission and retransmission), 5 bits of modulationand coding scheme information, 1 bit for a retransmission index, and abalance of reserved information bits so that the size of the SCI format1 message is 32-bits in total (the reserved bits are typically set to‘0’).

In order to reuse the SCI format 1 message to indicate atransmission-reception pattern, HARQ ACK/NACK feedback information, theSA function differentiation flag, and other information discussed above,one or more bit fields may be used to carry new information. In someembodiments, the 3 bits of priority information may be used to representthe HARQ process number (a 3-bit value) and the retransmission index maybe used to represent the new data indicator. In certain embodiments, the4 resource reservation bits may be used to indicate thetransmission-reception pattern. Where the transmission-reception patterncan be represented with 3 bits, the remaining resource reservation bitmay be used to represent the SA function differentiation flag. In otherembodiments, the reserved information bits may be used to indicate thetransmission-reception pattern and SA function differentiation flag.

In some embodiments, the priority bits and modulation and coding schemebits may be used to represent the decoding status (HARQ ACK/NACK) of 8HARQ process number in bitmap manner as discussed above. Additionally(or alternatively) bits of the reserved information bits may be used toindicate the HARQ ACK/NACK feedback indication.

FIG. 6 depicts one embodiment of a remote UE apparatus 600 that may beused for sidelink control information indication, according toembodiments of the disclosure. The remote UE apparatus 600 may be oneembodiment of the remote unit 105 and/or the remote UE 205. Furthermore,the remote UE apparatus 600 includes a processor 605, a memory 610, aninput device 615, a display 620, a transmitter 625, and a receiver 630.In some embodiments, the input device 615 and the display 620 arecombined into a single device, such as a touchscreen. In certainembodiments, the remote unit 105 may not include any input device 615and/or display 620.

The transmitter 625 and receiver 630 are used to communicate with arelay UE using sidelink communication. Here, the sidelink communicationis defined within preconfigured sidelink resource pools (PSCCH/PSSCH).Multiple pools can be configured by eNB for sidelink operation. In someembodiments, the sidelink communication uses frequency-divisionmultiplexing (“FDM”) between PSCCH and PSSCH, from both a UE and systemperspective. In other embodiments, the sidelink communication uses FDMbetween PSCCH and PSSCH from the system perspective, but usestime-division multiplexing (“TDM”) from the UE perspective.

The processor 605, in one embodiment, may include any known controllercapable of executing computer-readable instructions and/or capable ofperforming logical operations. For example, the processor 605 may be amicrocontroller, a microprocessor, a central processing unit (“CPU”), agraphics processing unit (“GPU”), an auxiliary processing unit, a fieldprogrammable gate array (“FPGA”), or similar programmable controller. Insome embodiments, the processor 605 executes instructions stored in thememory 610 to perform the methods and routines described herein. Theprocessor 605 is communicatively coupled to the memory 610, the inputdevice 615, the display 620, the transmitter 625, and the receiver 630.

In some embodiments, the receiver 630 receives an indicator of atransmission-reception pattern in a first control information message.The receiver 630 may also receive an indicator of scheduling assignmenttransmitted in the first control information message and associated datatransmitted in a data message from a relay unit. In response toreceiving one or more data processes (e.g., HARQ processes), theprocessor 605 generates an indicator of hybrid automatic repeat request(“HARQ”) feedback information. The processor 605 also determines atransmission subframe of the apparatus based on the received indicatorof a transmission-reception pattern. The processor 605 may then controlthe transmitter 625 to transmit the indicator of HARQ feedbackinformation to the relay unit in a second control information message ona remote unit transmission subframe determined from thetransmission-reception pattern.

In some embodiments, receiving the indicator of thetransmission-reception pattern includes the receiving a SCI format 1message and reinterpreting the SCI format 1 message to determine theindicator of the transmission-reception pattern. In one embodiment,receiving the indicator of the transmission-reception pattern includesreceiving the indicator of the transmission-reception pattern from therelay unit. In another embodiment, receiving the indicator of thetransmission-reception pattern includes receiving the indicator of thetransmission-reception pattern from a base unit.

In certain embodiments, the indicator of the transmission-receptionpattern may indicate a particular pattern selected from a plurality ofpredetermined patterns. In one embodiment, the indicator of thetransmission-reception pattern comprises a bitmap representing at leastone transmission subframe and at least one reception subframe in thetransmission-reception pattern. In another embodiment, the indicator ofthe transmission-reception pattern is an offset value pointing to a nextreception subframe in the transmission-reception pattern. In yet anotherembodiment, the indicator of the transmission-reception pattern is anoffset value pointing to a next transmission subframe in thetransmission-reception pattern.

In certain embodiments, the second control information message includesa scheduling assignment (“SA”) function differentiation flag thatindicates whether the second control information message includes HARQfeedback information and whether a data transmission is associated withthe second control information message. Additionally, the second controlinformation message may also include a data offset indicating a timeoffset between the second control information message and the associateddata transmission.

The memory 610, in one embodiment, is a computer readable storagemedium. In some embodiments, the memory 610 includes volatile computerstorage media. For example, the memory 610 may include a RAM, includingdynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or staticRAM (“SRAM”). In some embodiments, the memory 610 includes non-volatilecomputer storage media. For example, the memory 610 may include a harddisk drive, a flash memory, or any other suitable non-volatile computerstorage device. In some embodiments, the memory 610 includes bothvolatile and non-volatile computer storage media. In some embodiments,the memory 610 stores data relating to sidelink control informationindication, for example storing transmission-reception patterns,indicators, feedback information, and the like. In some embodiments, thememory 610 also stores program code and related data, such as anoperating system or other controller algorithms operating on the remoteunit 105 and one or more software applications.

The input device 615, in one embodiment, may include any known computerinput device including a touch panel, a button, a keyboard, a stylus, amicrophone, or the like. In some embodiments, the input device 615 maybe integrated with the display 620, for example, as a touchscreen orsimilar touch-sensitive display. In some embodiments, the input device615 includes a touchscreen such that text may be input using a virtualkeyboard displayed on the touchscreen and/or by handwriting on thetouchscreen. In some embodiments, the input device 615 includes two ormore different devices, such as a keyboard and a touch panel.

The display 620, in one embodiment, may include any known electronicallycontrollable display or display device. The display 620 may be designedto output visual, audible, and/or haptic signals. In some embodiments,the display 620 includes an electronic display capable of outputtingvisual data to a user. For example, the display 620 may include, but isnot limited to, an LCD display, an LED display, an OLED display, aprojector, or similar display device capable of outputting images, text,or the like to a user. As another, non-limiting, example, the display620 may include a wearable display such as a smart watch, smart glasses,a heads-up display, or the like. Further, the display 620 may be acomponent of a smart phone, a personal digital assistant, a television,a table computer, a notebook (laptop) computer, a personal computer, avehicle dashboard, or the like.

In certain embodiments, the display 620 includes one or more speakersfor producing sound. For example, the display 620 may produce an audiblealert or notification (e.g., a beep or chime). In some embodiments, thedisplay 620 includes one or more haptic devices for producingvibrations, motion, or other haptic feedback. In some embodiments, allor portions of the display 620 may be integrated with the input device615. For example, the input device 615 and display 620 may form atouchscreen or similar touch-sensitive display. In other embodiments,the display 620 may be located near the input device 615.

The transmitter 625 and receiver 630 operate under the control of theprocessor 605 to transmit messages, data, and other signals and also toreceive messages, data, and other signals. For example, the processor605 may selectively activate the transmitter 625 or receiver 630 (orportions thereof) at particular times in order to send and/or receivemessages. The remote UE apparatus 600 may include one or moretransmitters 625 and one or more receivers 630 for communicating withthe relay UE 120 (or relay UE 210).

FIG. 7 depicts one embodiment of a relay UE apparatus 700 that may beused for sidelink control information indication, according toembodiments of the disclosure. The relay UE apparatus 700 may be oneembodiment of the relay unit 120 and/or the relay UE 210. Furthermore,the relay UE apparatus 700 includes a processor 705, a memory 710, aninput device 715, a display 720, a transmitter 725, and a receiver 730.In some embodiments, the input device 715 and the display 720 arecombined into a single device, such as a touchscreen. In certainembodiments, the remote unit 105 may not include any input device 715and/or display 720.

The transmitter 725 and receiver 730 are used to communicate with arelay UE using sidelink communication. Here, the sidelink communicationis defined within preconfigured sidelink resource pools (PSCCH/PSSCH).Multiple pools can be configured by eNB for sidelink operation. In someembodiments, the sidelink communication uses frequency-divisionmultiplexing (“FDM”) between PSCCH and PSSCH, from both a UE and systemperspective. In other embodiments, the sidelink communication uses FDMbetween PSCCH and PSSCH from the system perspective, but usestime-division multiplexing (“TDM”) from the UE perspective.

The processor 705, in one embodiment, may include any known controllercapable of executing computer-readable instructions and/or capable ofperforming logical operations. For example, the processor 705 may be amicrocontroller, a microprocessor, a central processing unit (“CPU”), agraphics processing unit (“GPU”), an auxiliary processing unit, a fieldprogrammable gate array (“FPGA”), or similar programmable controller. Insome embodiments, the processor 705 executes instructions stored in thememory 710 to perform the methods and routines described herein. Theprocessor 705 is communicatively coupled to the memory 710, the inputdevice 715, the display 720, the transmitter 725, and the receiver 730.

In some embodiments, the receiver 730 receives a second controlinformation message from a remote unit over sidelink communication.Here, the second control information message is in response to theremote unit receiving one or more data processes scheduled by a firstcontrol information message from a relay unit, e.g., from the relay UEapparatus 700. The processor 705 determines a transmission-receptionpattern for the sidelink communication between the relay UE apparatus700 and the remote UE. The processor 705 also generates an indicator ofthe determined transmission-reception pattern. The processor 705 maythen control the transmitter 725 to transmit the indicator of thedetermined transmission-reception pattern to the remote unit in a thirdcontrol information message. In one embodiment, the first controlinformation message, the second control information message, and thethird control information message are transmitted in a same type ofcontrol channel (e.g., PSCCH).

In certain embodiments, the processor 705 determines thetransmission-reception pattern comprises by determining a ratio oftransmission payload to reception payload based on a buffer status ofrelay unit and/or a buffer status report of one or more remote units.The processor 705 may then generate the transmission-reception patternbased on one or more of: the ratio, the buffer status of relay unit, andthe buffer status report of one or more remote units.

In one embodiment, the indicator of the determinedtransmission-reception pattern comprises a bitmap representing at leastone transmission subframe and at least one reception subframe in thegenerated transmission-reception pattern. In another embodiment, theindicator of the determined transmission-reception pattern is an offsetvalue pointing to a next reception subframe in the generatedtransmission-reception pattern. In yet another embodiment, the indicatorof the determined transmission-reception pattern is an offset valuepointing to a next transmission subframe in the generatedtransmission-reception pattern.

In certain embodiments, the processor 705 determines thetransmission-reception pattern comprises by determining a ratio oftransmission payload to reception payload based on a buffer status ofrelay unit and/or a buffer status report of one or more remote units.The processor 705 may then the transmission-reception pattern from aplurality of predetermined patterns based on one or more of: the ratio,the buffer status of relay unit, and the buffer status report of one ormore remote units. Here, the indicator of the determinedtransmission-reception pattern may be a plurality of bits representingthe selected transmission-reception pattern. For example, specific bitvalues may be mapped to specific patterns among the plurality ofpredetermined patterns.

In some embodiments, third control information message includes anindicator of scheduling assignment (“SA”) function differentiation flag.Here, the SA function differentiation flag may indicate whether thethird control information message includes hybrid automatic repeatrequest (“HARQ”) feedback information. Where the third controlinformation message includes HARQ feedback information, the thirdcontrol information message may contain a bitmap representing HARQfeedback information corresponding to one or more HARQ processes.

In certain embodiments, the third control information message includesan indicator of scheduling assignment. Here, the indicator of schedulingassignment indicating an associated data transmission. In furtherembodiments, the third control information message may include a dataoffset indicating a time offset between the second SCI message and theassociated data transmission.

In some embodiments, generating an indicator of the determinedtransmission-reception pattern comprises the processor 705 generating aSCI format 1 message to be reinterpreted by the remote UE to indicatethe determined transmission-reception pattern. In such embodiments, theprocessor 705 may modify one or more bit fields of the SCI format 1message to indicate the transmission-reception pattern.

In certain embodiments, the receiver 730 further receives a fourthcontrol information message from the remote UE. Here, the fourth controlinformation message may include an indicator of whether the fourthcontrol information message contains (“HARQ”) feedback information. Thefourth control information message may also include an indicator ofwhether the fourth control information message is associated with a datatransmission from the remote UE.

The memory 710, in one embodiment, is a computer readable storagemedium. In some embodiments, the memory 710 includes volatile computerstorage media. For example, the memory 710 may include a RAM, includingdynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or staticRAM (“SRAM”). In some embodiments, the memory 710 includes non-volatilecomputer storage media. For example, the memory 710 may include a harddisk drive, a flash memory, or any other suitable non-volatile computerstorage device. In some embodiments, the memory 710 includes bothvolatile and non-volatile computer storage media. In some embodiments,the memory 710 stores data relating to sidelink control informationindication, for example storing transmission-reception patterns,indicators, feedback information, and the like. In certain embodiments,the memory 710 also stores program code and related data, such as anoperating system or other controller algorithms operating on the relayUE apparatus 700 and one or more software applications.

The input device 715, in one embodiment, may include any known computerinput device including a touch panel, a button, a keyboard, a stylus, amicrophone, or the like. In some embodiments, the input device 715 maybe integrated with the display 720, for example, as a touchscreen orsimilar touch-sensitive display. In some embodiments, the input device715 includes a touchscreen such that text may be input using a virtualkeyboard displayed on the touchscreen and/or by handwriting on thetouchscreen. In some embodiments, the input device 715 includes two ormore different devices, such as a keyboard and a touch panel.

The display 720, in one embodiment, may include any known electronicallycontrollable display or display device. The display 720 may be designedto output visual, audible, and/or haptic signals. In some embodiments,the display 720 includes an electronic display capable of outputtingvisual data to a user. For example, the display 720 may include, but isnot limited to, an LCD display, an LED display, an OLED display, aprojector, or similar display device capable of outputting images, text,or the like to a user. As another, non-limiting, example, the display720 may include a wearable display such as a smart watch, smart glasses,a heads-up display, or the like. Further, the display 720 may be acomponent of a smart phone, a personal digital assistant, a television,a table computer, a notebook (laptop) computer, a personal computer, avehicle dashboard, or the like.

In certain embodiments, the display 720 includes one or more speakersfor producing sound. For example, the display 720 may produce an audiblealert or notification (e.g., a beep or chime). In some embodiments, thedisplay 720 includes one or more haptic devices for producingvibrations, motion, or other haptic feedback. In some embodiments, allor portions of the display 720 may be integrated with the input device715. For example, the input device 715 and display 720 may form atouchscreen or similar touch-sensitive display. In other embodiments,the display 720 may be located near the input device 715.

The transmitter 725 and receiver 730 operate under the control of theprocessor 705 to transmit messages, data, and other signals and also toreceive messages, data, and other signals. For example, the processor705 may selectively activate the transmitter 725 or receiver 730 (orportions thereof) at particular times in order to send and/or receivemessages. The relay UE apparatus 700 may include one or moretransmitters 725 and one or more receivers 730 for communicating with aremote UE 105 and/or a base unit 110 of a mobile communication network.

FIG. 8 depicts a method 800 for sidelink control information indication,according to embodiments of the disclosure. In some embodiments, themethod 800 is performed by an apparatus, such as the relay unit 120, therelay UE 210, and/or relay UE apparatus 700. In certain embodiments, themethod 800 may be performed by a processor executing program code, forexample, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliaryprocessing unit, a FPGA, or the like.

The method 800 begins and receives 805 second control informationmessage from a remote unit over sidelink communication. Here, the secondcontrol information message is in response to the remote unit receivingone or more data processes scheduled by a first control informationmessage from a relay unit. In some embodiments, the first controlinformation message includes a transmission-reception pattern, whereinthe second control information message is received during a receptionperiod of the transmission-reception pattern.

The method 800 includes determining 810 a transmission-reception patternfor a remote unit using sidelink communication. In some embodiments,determining 810 the transmission-reception pattern includes determininga ratio of transmission payload to reception payload based on a bufferstatus of relay unit and/or a buffer status report of one or more remoteunits, and further generating the transmission-reception pattern basedone or more of: on the ratio, the buffer status of relay unit, and thebuffer status report of one or more remote units. In certainembodiments, determining the transmission-reception pattern includesselecting the transmission-reception pattern from a plurality ofpredetermined patterns based one or more of: on the ratio, the bufferstatus of relay unit, and the buffer status report of one or more remoteunits, wherein the indicator of the determined transmission-receptionpattern comprises a plurality of bits representing the selectedtransmission-reception pattern.

The method 800 includes generating 815 an indicator of the determinedtransmission-reception pattern. In some embodiments, generating 815 anindicator of the determined transmission-reception pattern includesgenerating a SCI format 1 message to be reinterpreted by the remote unitto indicate the determined transmission-reception pattern.

In one embodiment, the indicator of the determinedtransmission-reception pattern comprises a bitmap representing at leastone transmission subframe and at least one reception subframe in thegenerated transmission-reception pattern. In another embodiment, theindicator of the determined transmission-reception pattern is an offsetvalue pointing to a next reception subframe in the generatedtransmission-reception pattern. In yet another embodiment, the indicatorof the determined transmission-reception pattern is an offset valuepointing to a next transmission subframe in the generatedtransmission-reception pattern. Where the transmission-reception patternis selected from a plurality of predetermined patterns, the indicator ofthe determined transmission-reception pattern may be a plurality of bitsrepresenting the selected transmission-reception pattern.

The method 800 includes transmitting 820 the indicator to the remoteunit in a third control information message. In one embodiment, thefirst control information message, the second control informationmessage, and the third control information message are transmitted in asame type of control channel (e.g., PSCCH). In certain embodiments, thethird control information message includes an indicator of schedulingassignment (“SA”) function differentiation flag, the SA functiondifferentiation flag indicating that the third control informationmessage includes hybrid automatic repeat request (“HARQ”) feedbackinformation. Here, the third control information message may include abitmap representing the HARQ feedback information in response to one ormore HARQ process.

In some embodiments, the third control information message includes anindicator of scheduling assignment, the indicator of schedulingassignment indicating that a data transmission is associated with thethird control information message. Here, the third control informationmessage may further include a data offset indicating a time offsetbetween the third control information message and the associated datatransmission. In certain embodiments, the remote unit sends a fourthcontrol information message in response to the transmitting 820 of theindicator to the remote unit. Here, the fourth control informationmessage includes an indicator of whether the fourth control informationmessage contains (“HARQ”) feedback information. In further embodiments,the fourth control information message may include an indicator ofwhether the fourth control information message is associated with a datatransmission from the remote unit. The method 800 ends.

FIG. 9 depicts a method 900 for sidelink control information indication,according to embodiments of the disclosure. In some embodiments, themethod 900 is performed by an apparatus, such as the remote unit 105,the remote UE 205, and/or the remote UE apparatus 600. In certainembodiments, the method 900 may be performed by a processor executingprogram code, for example, a microcontroller, a microprocessor, a CPU, aGPU, an auxiliary processing unit, a FPGA, or the like.

The method 900 begins and receives 905 an indicator of atransmission-reception pattern in a first control information message.In one embodiment, the first control information message is a sidelinkcontrol information (“SCI”) message. In another embodiment, the firstcontrol information message is a downlink control information (“DCI”)message.

The method 900 includes receiving 910 an indicator of schedulingassignment transmitted in the first control information message andassociated data transmitted in a data channel from a relay unit. In oneembodiment, the associated data is received via a sidelink data message.In some embodiments, receiving 910 the indicator of thetransmission-reception pattern comprises receiving a SCI format 1message and reinterpreting the SCI format 1 message to determine theindicator of the transmission-reception pattern. In one embodiment,receiving 910 the indicator of the transmission-reception patterncomprises receiving the indicator of the transmission-reception patternfrom the relay unit. In another embodiment, receiving 910 the indicatorof the transmission-reception pattern comprises receiving the indicatorof the transmission-reception pattern from a base unit.

The method 900 includes generating 915 an indicator of hybrid automaticrepeat request (“HARQ”) feedback information in response to the receivedone or more data processes. In one embodiment, the one or more dataprocesses are one or more HARQ processes. In some embodiments, theindicator of the transmission-reception pattern indicates a particularpattern selected from a plurality of predetermined patterns. In oneembodiment, the indicator of the transmission-reception patterncomprises a bitmap representing at least one transmission subframe andat least one reception subframe in the transmission-reception pattern.In another embodiment, the indicator of the transmission-receptionpattern is an offset value pointing to a next reception subframe in thetransmission-reception pattern. In yet another embodiment, the indicatorof the transmission-reception pattern is an offset value pointing to anext transmission subframe in the transmission-reception pattern.

The method 900 includes determining 920 a transmission subframe of theapparatus based on the received indicator of a transmission-receptionpattern. The method 900 includes transmitting 925 the indicator of HARQfeedback information to the relay unit in a second control informationmessage on a transmission subframe of remote unit determined from thetransmission-reception pattern. In one embodiment, the second controlinformation message is a SCI message. In some embodiments, the secondcontrol information message includes a scheduling assignment (“SA”)function differentiation flag that indicates whether the second controlinformation message includes HARQ feedback information and whether adata transmission is associated with the second control informationmessage. In certain embodiments, the second control information messagefurther includes a data offset indicating a time offset between thesecond control information message and the associated data transmission.The method 900 ends.

Embodiments may be practiced in other specific forms. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. An apparatus comprising: a receiver that: receives a second controlinformation message from a remote unit over sidelink communication,wherein the second control information message is in response to theremote unit receiving one or more data processes scheduled by a firstcontrol information message from a relay unit; a processor that:determines a transmission-reception pattern for the sidelinkcommunication; generates an indicator of the determinedtransmission-reception pattern; and a transmitter that: transmits theindicator of the determined transmission-reception pattern to the remoteunit in a third control information message.
 2. The apparatus of claim1, wherein the first control information message, the second controlinformation message, and the third control information message aretransmitted in a same type of control channel.
 3. The apparatus of claim1, wherein determining the transmission-reception pattern comprises theprocessor: determining a ratio of transmission payload to receptionpayload based on one of a buffer status of relay unit and a bufferstatus report of one or more remote units; and generating thetransmission-reception pattern based on one or more of: the ratio, thebuffer status of relay unit, and the buffer status report of one or moreremote units.
 4. The apparatus of claim 3, wherein the indicator of thedetermined transmission-reception pattern comprises a bitmaprepresenting at least one transmission timeslot and at least onereception timeslot in the generated transmission-reception pattern. 5.The apparatus of claim 3, wherein the indicator of the determinedtransmission-reception pattern is an offset value pointing to a nextreception timeslot in the generated transmission-reception pattern or toa next transmission timeslot in the generated transmission-receptionpattern.
 6. (canceled)
 7. The apparatus of claim 1, wherein determiningthe transmission-reception pattern comprises the processor: determininga ratio of transmission payload to reception payload based on one of: abuffer status of relay unit and a buffer status report of one or moreremote units; and selecting the transmission-reception pattern from aplurality of predetermined patterns based on one or more of: the ratio,the buffer status of relay unit, and the buffer status report of one ormore remote units, wherein the indicator of the determinedtransmission-reception pattern comprises a plurality of bitsrepresenting the selected transmission-reception pattern.
 8. Theapparatus of claim 1, wherein the third control information messageincludes an indicator of scheduling assignment (“SA”) functiondifferentiation flag, the SA function differentiation flag indicatingthat the third control information message includes hybrid automaticrepeat request (“HARQ”) feedback information.
 9. The apparatus of claim8, wherein the third control information message includes a bitmaprepresenting the HARQ feedback information in response to one or moreHARQ processes.
 10. The apparatus of claim 1, wherein the third controlinformation message includes an indicator of scheduling assignment, theindicator of scheduling assignment indicating an associated datatransmission.
 11. The apparatus of claim 10, wherein the third controlinformation message further includes a data offset indicating a timeoffset between the third control information message and the associateddata transmission.
 12. (canceled)
 13. The apparatus of claim 1, whereinthe receiver further receives a fourth control information message fromthe remote unit, the fourth control information message including anindicator of whether the fourth control information message containshybrid automatic repeat request (“HARQ”) feedback information.
 14. Theapparatus of claim 13, wherein the fourth control information messagefurther includes an indicator of whether the fourth control informationmessage is associated with a data transmission from the remote unit. 15.(canceled)
 16. (canceled)
 17. (canceled)
 18. (canceled)
 19. (canceled)20. (canceled)
 21. (canceled)
 22. (canceled)
 23. (canceled) 24.(canceled)
 25. (canceled)
 26. (canceled)
 27. (canceled)
 28. (canceled)29. An apparatus comprising a receiver that: receives an indicator of atransmission-reception pattern in a first control information message;receives an indicator of scheduling assignment transmitted in the firstcontrol information message and associated data transmitted in a datamessage from a relay unit; a processor that: generates an indicator ofhybrid automatic repeat request (“HARQ”); feedback information inresponse to receiving one or more data processes; determines atransmission timeslot of the apparatus based on the received indicatorof a transmission-reception pattern; and a transmitter that: transmitsthe indicator of HARQ feedback information to the relay unit in a secondcontrol information message on the determined transmission timeslot ofthe apparatus.
 30. The apparatus of claim 29, wherein receiving theindicator of the transmission-reception pattern comprises the processorreceiving the indicator of the transmission-reception pattern from therelay unit.
 31. The apparatus of claim 29, wherein receiving theindicator of the transmission-reception pattern comprises the processorreceiving the indicator of the transmission-reception pattern from abase unit.
 32. The apparatus of claim 29, wherein the indicator of thetransmission-reception pattern comprises a bitmap representing at leastone transmission timeslot and at least one reception timeslot in thetransmission-reception pattern.
 33. The apparatus of claim 29, whereinthe indicator of the transmission-reception pattern is an offset valuepointing to a next reception timeslot in the transmission-receptionpattern or to a next transmission timeslot in the generatedtransmission-reception pattern.
 34. (canceled)
 35. The apparatus ofclaim 29, wherein the indicator of the transmission-reception patternindicates a particular pattern selected from a plurality ofpredetermined patterns.
 36. The apparatus of claim 29, wherein thesecond control information message includes a scheduling assignment(“SA”) function differentiation flag that indicates whether the secondcontrol information message includes HARQ feedback information andwhether a data transmission is associated with the second controlinformation message.
 37. The apparatus of claim 36, wherein the secondcontrol information message further includes a data offset indicating atime offset between the second control information message and theassociated data transmission.
 38. (canceled)
 39. (canceled) 40.(canceled)
 41. (canceled)
 42. (canceled)
 43. (canceled)
 44. (canceled)45. (canceled)
 46. (canceled)
 47. (canceled)
 48. (canceled)